Journal of Veterinary and Animal Sciences

Volume: 55 Issue: 1

  • Open Access
  • Research Article

Antibiogram of Enterococcus sp. isolated from household thayir sample

S.R. Aiswarya1*, A.K. Beena1, S.V. Aparana1, C. Archana2 and C.H. Aysha1

1. Department of Dairy Microbiology Verghese Kurien Institute of Dairy and Food Technology, Mannuthy, Thrissur, Pin-680651

2. Department of Dairy Microbiology, CDST, KAVSU, Pookode

Kerala Veterinary and Animal Sciences University Kerala, India

*Corresponding author: [email protected], Ph.9497131103

Year: 2024, Page: 57-64, Doi:

Received: Sept. 21, 2023 Accepted: Nov. 24, 2023 Published: March 31, 2024


The present study aimed to evaluate the antibiotic susceptibility of Enterococcus sp. isolated from a household dahi/thayir sample. Bile esculin agar was used for the selective isolation of Enterococcus sp. Based on biochemical characterization and 16SrRNA sequencing, the isolate was identified as Enterococcus faecium, the sequence of which is deposited in NCBI with accession number OR105180. Enterococcus faecium was found to be resistant to Penicillin, Ampicillin, Vancomycin, Tetracycline, and Erythromycin. Multiple Antibiotic Resistance (MAR) index of the isolate was found to be 0.625. Minimum inhibitory concentration for Penicillin, Ampicillin, Vancomycin, Tetracycline and Erythromycin exceeded the break point established by CLSI guidelines. Microtiter plate assay revealed the isolate to be a weak biofilm former. Safety assessment revealed the isolate to be alpha haemolytic with no gelatinase activity. The observations endorse the possibility of household dahi/thayir samples being a potential reservoir for the dissemination of antibiotic resistance to human gut microflora.

Keywords: Enterococcus faecium, antibiotic resistance, multiple antibiotic resistance (MAR) index


Abdulla, F.E. and Abdulla, E.M. 2006. Antibiotic options for Enterococcus faecalis infections. Pakistan J.  Med. Sci. 22: 286–290

Arabestani, M.R., Mousavi, S.M., Hosseini, S.M. and Nasaj, M. 2016. Prevalence of virulence factors and vancomycin-resistant genes among E. faecalis and E. faecium isolated from clinical specimens. Iranian J. Public Hlth. 45: 806.

Ball, R.J. and Sellers, W. 1966. Improved motility medium. Appl. Microbiol. 14: 670-673.

Barbosa, J., Gibbs, P.A. and Teixeira, P. 2010. Virulence factors among Enterococci isolated from traditional fermented meat products produced in the North of Portugal. Food Control. 21

Barrow, C.I. and Feltham, R.K.A. 1993. Cowan and Steel’s; Manual for the Identification of Medical Bacteria. (3rd Ed). Cambridge University Press. pp. 68- 76.

Bauer, A.W., Kirby, W.M.M., Sherris, J.C. and Turk, M. 1966. Antibiotic susceptibility testing by a standardized single disk method. Am. J. Clin. Pathol. 45: 493–496.

Chandran, A., Beena, A.K., Bhagya, S., Rathish, R.L. and Rahila, M.P. 2022. Probiotic characterisation of Enterococcus faecalis strain isolated from a household Dahi sample of Wayanad district, Kerala. J. Vet. Anim. Sci53: 70-8.

Chingwaru, W., Mpuchane, S.F. and Gashe, B.A. 2003. Enterococcus faecalis and Enterococcus faecium isolates from milk, beef, and chicken and their antibiotic resistance. J. Food. Prot. 66: 931-936.

 CLSI. 2020. Performance Standards for Antimicrobial Testing. 30th Ed. Clinical and Laboratory Standard Institute; Wayne, PA.

Facklam, R.R. and Collins, M.D.1989. Identification of Enterococcus sp. isolated from human infections by a conventional test scheme. J. Clin. Microbiol. 27: 731-734.

Founou, L.L., Founou, R.C. and Essack, S.Y. 2016. Antibiotic resistance in the food chain: a developing country-perspective. Front. microbiol. 7: 1881.

Freeman, D.J., Falkiner, F.R. and Keane, C.T. 1989. New method for detecting slime production by coagulase negative Staphylococci. J. Clin. Pathol. 42:  872- 874.

Hanchi, H., Mottawea, W., Sebei, K. and Hammami, R. 2018. The genus Enterococcus: between probiotic potential and safety concerns-an update. Front. Microbiol. 9: 1791.

Hou, W., Sun, X., Wang, Z. and Zhang, Y. 2012. Biofilm-forming capacity of Staphylococcus epidermidis, Staphylococcus aureus, and Pseudomonas aeruginosa from ocular infections. Invest. Ophthalmol. Visual Sci. 53: 5624-5631.

Jacob, J., Rajendran, R.U., Priya, S.H., Purushothaman, J. and Saraswathy Amma D.K. 2017. Enhanced antibacterial metabolite production through the application of statistical methodologies by a Streptomyces nogalater NIIST A30 isolated from Western Ghats forest soil. PLoS One. 12: e0175919

Koch, S., Hufnagel, M., Theilacker, C. and Huebner, J. 2004. Enterococcal infections: host response, therapeutic, and prophylactic possibilities. Vaccine. 22: 822-830.

Krumperman, P.H. 1983. Multiple antibiotic resistance indexing of Escherichia coli to identify high-risk sources of fecal contamination of foods. Appl. Environ. Microbiol. 46: 165–170.

Magiorakos, A.P., Srinivasan, A., Carey, R.B., Carmeli, Y., Falagas, M.E., Giske, C.G., Harbarth, S., Hindler, J.F., Kahlmeter, G., Olsson-Liljequist, B. and Paterson, D.L. 2012. Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance. Clin. Microbiol. Infect. 18: 268-281.

Mah, T.F. 2012. Biofilm specific antibiotic resistance. Future Microbiol. 92: 98-110

Manero, A. and Blanch, A.R. 1999. Identification of Enterococcus spp. with a biochemical key. Appl. Environ. Microbiol. 65: 4425-4430.

Ramsey, M., Hartke, A. and Huycke, M. 2014. The physiology and metabolism of enterococci. Enterococci: From Commensals to Leading Causes of Drug Resistant Infection

Sahu, K.A., Nemani, R., Sinha, R. and Pradhan, P. 2019. Isolation and characterization of probiotic from fermented rice, idly and dosa batter and screening of antimicrobial activity. Int. J. Chem. Tech Res. 12: 52-58.

Sharma, P., Tomar, S.K., Goswami, P., Sangwan, V. and Singh, R. 2014. Antibiotic resistance among commercially available probiotics. Food Res. Int. 57: 176-195.

Stepanovic, S., Vukovic, D., Dakic, I., Savic, B. and Svabic-Vlahovic, M. 2000. A modified microtiter-plate test for quantification of staphylococcal biofilm formation. J. Microbiol. Meth. 40: 175-179.

Tsveteslava, I. 2017. Exopolysaccharides from Bacteria with Novel Application. In: Krasimir Metodiev (ed). Immunotherapy - Myths, Reality, Ideas, Future. (1st Ed). InTech, Editors. pp.345-354.

Vincent, S., Knight, R.G., Green, M., Sahm, D.F. and Shlaes, D.M. 1991. Vancomycin susceptibility and identification of motile enterococci.  J. Clin. Microbiol . 29: 2335-2337.

Cite this article

Aiswarya, S.R., Beena, A.K. Aparana, S.V., Archana, C. and Aysha, C.H. 2024. Antibiogram of Enterococcus sp. isolated from household thayir sample. J. Vet. Anim. Sci. 55(1):57-64